Such a transformer can comprise a plurality of windings arranged in a regulating transformer, for example as at least one primary winding and at least one regulating winding with a plurality of winding taps. In the switching arrangement according to the invention the preselector is provided for the purpose of connecting a first winding of the transformer selectably with one of the two ends of a second winding for subtractive or additive coupling of the windings. In addition, the switching arrangement according to the invention has a polarity circuit that connects a defined point of the second winding, for example a center tap or one of the two end taps, with the first winding or a load diverter by a polarity resistance. The idea of the polarity circuit is to bring the second winding to a defined potential. A circuit of that kind is also known from DE 32 24 860. The polarity circuit with the polarity resistance has the consequence of a significantly smaller arc formation during switching over of the preselector, which in the case of tap changers in an oil bath environment leads to a significantly smaller induction of gas into the oil bath. However, a loss current constantly flows by the polarity resistance, which has the consequence that the polarity resistance heats and can lead to heating of the surrounding oil medium and in addition the effectiveness of the transformer is reduced.